Plasmin is an enzyme which plays an important role in the inflammatory process by activating vasoaotive amine and lysis of fibrin. On the other hand, plasmin is also known to activate latent collagenase. Plasmin is an activated form of plasminogen which is stimulated by the plasminogen activator that exists in plasma and tissue. Gordon et at (1980) insisted that collagenase is important for the formation of corneal ulcer because it destroys the collagen which is the main component of the cornea. Berman et al(1980)reported that corneal tissue destruction by plasminogen activator-plasmin system can be a cause of corneal ulcer. We could obtain the following results by checking the plasmin activity in the tear of chronic corneal ulcer patients and necrotizing scleritis patients.
1. The plasmin activity in the tear was increased in all three chronic corneal ulcer patients in concentration of 1/16 sigma unit/ml to 1/8 sigma unit/ml.
2. There was no plasmin activity in the tear of the two necrotizing scleritis patients.